U.S. patent application number 16/031504 was filed with the patent office on 2018-11-08 for adhesive compositions.
The applicant listed for this patent is HENKEL IP & HOLDING GMBH. Invention is credited to Brian DEEGAN, Marc GALLIGAN, Lynnette HURLBURT, Andrew D. MESSANA, Nigel SWEENEY.
Application Number | 20180320025 16/031504 |
Document ID | / |
Family ID | 63857054 |
Filed Date | 2018-11-08 |
United States Patent
Application |
20180320025 |
Kind Code |
A1 |
SWEENEY; Nigel ; et
al. |
November 8, 2018 |
ADHESIVE COMPOSITIONS
Abstract
The present invention provides adhesive compositions, sometimes
in a two part configuration which include a first part containing a
(meth)acrylate component, an organic peroxide and an
acetal-containing free radically curable component and a second
part containing a (meth)acrylate component, and benzoylthiourea
derivatives or benzoylthiourethane derivatives.
Inventors: |
SWEENEY; Nigel; (Dublin,
IE) ; DEEGAN; Brian; (Dublin, IE) ; HURLBURT;
Lynnette; (Manchester, CT) ; MESSANA; Andrew D.;
(Newington, CT) ; GALLIGAN; Marc; (Dublin,
IE) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
HENKEL IP & HOLDING GMBH |
Duesseldorf |
|
DE |
|
|
Family ID: |
63857054 |
Appl. No.: |
16/031504 |
Filed: |
July 10, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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PCT/US2018/027907 |
Apr 17, 2018 |
|
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16031504 |
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62488354 |
Apr 21, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C08K 5/14 20130101; C09J
153/005 20130101; C09J 2433/00 20130101; C09J 4/00 20130101; C09J
151/003 20130101; C08K 5/405 20130101; C08F 279/04 20130101; C09J
11/06 20130101; C08F 279/04 20130101; C08F 220/06 20130101; C08F
279/04 20130101; C08F 222/102 20200201; C08F 279/04 20130101; C08F
222/1006 20130101; C08F 279/04 20130101; C08F 220/281 20200201;
C08F 279/04 20130101; C08F 222/102 20200201 |
International
Class: |
C09J 4/00 20060101
C09J004/00; C09J 11/06 20060101 C09J011/06; C09J 153/00 20060101
C09J153/00 |
Claims
1. An adhesive composition in a two part configuration comprising:
(a) Part (A) comprising a (meth)acrylate component, an organic
peroxide and an acetal-containing free radically curable component;
and (b) Part (B) comprising a (meth)acrylate component, and
benzoylthiourea derivatives or benzoylthiourethane derivatives.
2. The adhesive composition of claim 1, wherein the
acetal-containing free radically curable component is represented
by compounds within the general structure below: ##STR00020##
wherein R.sup.1 is H, CH.sub.3 or CN; R.sup.2 is a multivalent
C.sub.1 to C.sub.8 alkyl chain, C.sub.6 to C.sub.12 aryl group or
C.sub.3 to C.sub.8 cycloalkyl group; and n is 1-4.
3. The composition of claim 1, wherein the acetal-containing free
radically curable component is represented by compounds within the
general structure below: ##STR00021## wherein R.sup.1 is C.sub.1 to
C.sub.30 alkyl, C.sub.6 to C.sub.30 aryl, ester, or carbamate; and
R.sup.2 is a divalent unsaturated C.sub.2-C.sub.40 linkage (such as
may be derived from a dicarboxylic acid selected from maleic acid,
fumaric acid, itaconic acid, glutaconic acid, traumatic acid,
glutinic acid and mesaconic acid.
4. The composition of claim 1, wherein the acetal-containing free
radically curable component is represented by compounds within the
general structure below: ##STR00022## wherein R.sup.1 is C.sub.1 to
C.sub.8 alkyl, C.sub.6 to C.sub.12 aryl or C.sub.3 to C.sub.8
cycloalkyl; and R.sup.2 is a divalent unsaturated C.sub.2-C.sub.60
linkage.
5. The composition of claim 4, wherein R.sup.2 of the
acetal-containing free radically curable component is derived from
a tricarboxylic acid selected from citric acid, isocitric acid,
aconitic acid and trimesic acid.
6. The composition of claim 1, wherein the acetal-containing free
radically curable component is represented by compounds selected
from the group consisting of ##STR00023##
7. The composition of claim 1, wherein the (meth)acrylate component
of at least one of the Part (A) or the Part (B) is selected from
the group consisting of methyl (meth)acrylate, (meth)acrylic acid,
ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl
(meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate,
tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl
(meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate,
n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl
(meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate,
phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl (meth)acrylate,
2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate,
2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl
(meth)acrylate, y-(meth)acryloyloxypropyl trimethoxysilane,
(meth)acrylic acid-ethylene oxide adduct, trifluoromethylmethyl
(meth)acrylate, 2-trifluoromethylethyl (meth)acrylate,
2-perfluoroethylethyl (meth)acrylate,
2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate,
2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate,
diperfluoromethylmethyl (meth)acrylate,
2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate,
2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl
(meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate,
ethoxylated trimethylolpropane triacrylate, trimethylol propane
trimethacrylate, dipentaerythritol monohydroxypentacrylate,
pentaerythritol triacrylate, ethoxylated trimethylolpropane
triacrylate, 1,6-hexanedioldiacrylate, neopentyl glycoldiacrylate,
pentaerythritol tetraacrylate, 1,2-butylene glycoldiacrylate,
trimethylopropane ethoxylate tri(meth)acrylate, glyceryl
propoxylate tri(meth)acrylate, trimethylolpropane
tri(meth)acrylate, dipentaerythritol monohydroxy
penta(meth)acrylate, tri(propylene glycol) di(meth)acrylate,
neopentylglycol propoxylate di(meth)acrylate, 1,4-butanediol
di(meth)acrylate, polyethyleneglycol di(meth)acrylate,
triethyleneglycol di(meth)acrylate, butylene glycol
di(meth)acrylate, ethoxylated bisphenol A di(meth)acrylate, and
combinations thereof.
8. The composition of claim 1, wherein the benzoylthiourea
derivatives or benzoylthiourethane derivatives are represented by
compounds within the general structure below: ##STR00024## wherein
Z is O or N--R, where R is selected from hydrogen, alkyl, alkenyl,
hydroxyalkyl, hydroxyalkenyl, carbonyl, alkylene (meth)acrylate,
carboxyl, or sulfonato, or R' is a direct bond attaching to the
phenyl ring; R' is selected from hydrogen, alkyl, alkenyl,
cycloalkyl, aryl, hydroxyalkyl, hydroxyalkenyl, alkylene- or
alkenylene-ether, carbonyl, alkylene (meth)acrylate, carboxyl,
nitroso or sulfonato; X is halogen, alkyl, alkenyl, hydroxyalkyl,
hydroxyalkenyl, alkoxy, amino, carboxyl, nitroso, sulfonate,
hydroxyl or haloalkyl; and Y is --SO.sub.2NH--, --CONH--, --NH--,
and --PO(NHCONHCSNH.sub.2)NH--; and n is 0 or 1 and m is 1 or 2; or
##STR00025## wherein R and R' are independently selected from
hydrogen, alkyl, alkenyl, aryl, hydroxyalkyl, hydroxyalkenyl,
alkylene (meth)acrylate, carbonyl, carboxyl, or sulfonato, or R and
R' taken together form a carbocyclic or hetero atom-containing
ring, or R' is a direct bond attaching to the phenyl ring; X is
halogen, alkyl, alkenyl, cycloalkyl, hydroxyalkyl, hydroxyalkenyl,
alkoxy, amino, alkylene- or alkenylene-ether, alkylene
(meth)acrylate, carbonyl, carboxyl, nitroso, sulfonate, hydroxyl or
haloalkyl; and Y is --SO.sub.2NH--, --CONH--, --NH--, and
--PO(NHCONHCSNH.sub.2)NH--; and n is 0 or 1 and m is 1 or 2.
9. The composition of claim 1, wherein the benzoylthiourea
derivatives or benzoylthiourethane derivatives are represented by
compounds within the general structure below: ##STR00026## wherein
R, X, Y, and n are as defined above, and X' is defined as X.
10. The composition of claim 1, wherein the benzoylthiourea
derivatives or benzoylthiourethane derivatives are represented by
compounds within the general structure below: ##STR00027## wherein
R, R', X, Y, and n are as defined above, and m is 2.
11. The adhesive composition of claim 1, further comprising a block
copolymer.
12. A method of preparing a two-part adhesive composition
comprising: (a) forming Part (A) comprising a (meth)acrylate
component, an organic peroxide and an acetal-containing free
radically curable component; and (b) forming Part (B) comprising a
(meth)acrylate component, and benzoylthiourea derivatives or
benzoylthiourethane derivatives.
13. A method of bonding a first surface to a second surface,
comprising: providing a two part composition comprising: (a) Part
(A) comprising a (meth)acrylate component, an organic peroxide and
an acetal-containing free radically curable component; and (b) Part
(B)comprising a (meth)acrylate component, and benzoylthiourea
derivatives or benzoylthiourethane derivatives.
14. The method of claim 13, wherein when Part (A) and Part (B) are
mixed and applied to at least one substrate, the composition will
have up to 5 minutes of open time and when the substrates are mated
they will have a cure time of about 20 minutes or less at
80.degree. C.; and a fixture time of less than 5 minutes at which
the bond will support 3 Kg.
15. The method of claim 13, wherein Part (A) and Part (B) are mixed
in a ratio of 1:10 to 10:1 Part (A) to Part (B) by volume.
16. An adhesive composition comprising: (a) a (meth)acrylate
component; (b) a cure package comprising an organic peroxide and
benzoylthiourea derivatives or benzoylthiourethane derivatives; and
(c) an acetal-containing free radically curable component.
17. The composition of claim 1, further comprising a reactive acid
component.
18. The composition of claim 17, wherein the reactive acid
component is (meth)acrylic acid.
19. The composition of claim 17, wherein the reactive acid
component is sulphonic acid or sulphonic acid derivatives,
phosphoric acid, phosphoric acid derivatives, and phosphate esters,
or acrylic acid.
Description
BACKGROUND
Field
[0001] The present invention provides adhesive compositions,
sometimes in a two part configuration which include a first part
containing a (meth)acrylate component, an organic peroxide and an
acetal-containing free radically curable component, and a second
part containing a (meth)acrylate component, and benzoylthiourea
derivatives or benzoylthiourethane derivatives.
Brief Description of Related Technology
[0002] Acrylic-based adhesive compositions are well known. See e.g.
U.S. Pat. No. 4,536,546 (Briggs). While adhesives based on this
technology appear to have been sold under the tradename PLEXUS MA
300 and 310 by Illinois Tool Works Inc., Chicago, Ill., they can
exhibit an obnoxious odor and they are toxic to handle, which are
significant drawbacks to their use.
[0003] The first and second parts are of sufficiently low viscosity
to be easily dispensed with a pumping apparatus. To form this
adhesive, the first and second parts are mixed, and immediately
after mixing, the mixture is of a higher viscosity, such that the
adhesive does not sag, drip, or migrate, after application to a
surface within the open time of the mixture, and the mixed first
and second parts cure. By the term "open time" is meant the elapsed
time between the mixture of the adhesive to the curing.
[0004] Recently, researchers at Henkel invented and developed a
cure accelerator technology based on benzoylthiourea or
benzoylthiourethane derivatives. U.S. Patent Application
Publication No. US 2014/0004354 provides to that end a two part
curable composition comprising:
[0005] Part A: one or more compounds within structures I or IA
below:
##STR00001##
wherein Z is O or N--R, where R is selected from hydrogen, alkyl,
alkenyl, aryl, hydroxyalkyl, hydroxyalkenyl, alkylene
(meth)acrylate, carbonyl, carboxyl, or sulfonato, R' is selected
from hydrogen, alkyl, alkenyl, aryl, hydroxyalkyl, hydroxyalkenyl,
alkylene (meth)acrylate, carbonyl, carboxyl, or sulfonato, or R and
and R' taken together form a carbocyclic or hetero atom-containing
ring, or R' is a direct bond attaching to the phenyl ring; X is
halogen, alkyl, alkenyl, cycloalkyl, hydroxyalkyl, hydroxyalkenyl,
alkoxy, amino, alkylene- or alkenylene-ether, alkylene
(meth)acrylate, carbonyl, carboxyl, nitroso, sulfonate, hydroxyl or
haloalkyl; and Y is --SO.sub.2NH--, --CONH--, --NH--, and
--PO(NHCONHCSNH.sub.2)NH--; and n is 0 or 1 and m is 1 or 2, or
##STR00002##
wherein R and R' are independently selected from hydrogen, alkyl,
alkenyl, aryl, hydroxyalkyl, hydroxyalkenyl, alkylene
(meth)acrylate, carbonyl, carboxyl, or sulfonato, or R and R' taken
together form a carbocyclic or hetero atom-containing ring, or R'
is a direct bond attaching to the phenyl ring; X is halogen, alkyl,
alkenyl, cycloalkyl, hydroxyalkyl, hydroxyalkenyl, alkoxy, amino,
alkylene- or alkenylene-ether, alkylene (meth)acrylate, carbonyl,
carboxyl, sulfonate, hydroxyl or haloalkyl; and Y is
--SO.sub.2NH--, --CONH--, --NH--, and --PO(NHCONHCSNH.sub.2)NH--;
and n is 0 or 1 and m is 1 or 2; and
[0006] Part B: an oxidant, where at least one of Part A or Part B
comprises a (meth)acrylate component.
[0007] However, existing compositions do not possess the desired
fast fixturing and good adhesion properties for the assembly of
laminates, such as hand held display devices, coupled with the
ability to enable debonding of substrates adhesively mated with the
composition therebetween. A need exists for such compositions.
[0008] There is also a need for adhesive compositions that can form
a robust bond on and/or between a variety of substrates, such as
ink coated glass, composites and engineering plastics, that also
have the ability to debond when required. In this way, should the
end-user need to reuse, recycle or remove parts they may be so. For
thermally activated debonding, temperatures below 100.degree. C.
are preferred so as to not damage the substrates.
[0009] The state of the art seemingly has not provided such
adhesive compositions.
SUMMARY
[0010] The present invention provides a solution to that need, and
more.
[0011] The inventive adhesive compositions, sometimes in a two part
configuration, include a first part (A) containing a (meth)acrylate
component, an organic peroxide and an acetal-containing
(meth)acrylate component and a second part (B) containing a
(meth)acrylate component, and benzoylthiourea derivatives or
benzoylthiourethane derivatives.
[0012] When the first and second parts are mixed and applied to at
least one substrate to be adhesively mated, the composition will
have up to 5 minutes of open time and when the substrates are mated
they will show a fixture time of about 5 minutes of less at about
room temperature (23.degree. C.)
[0013] More specifically, a two part adhesive composition is
provided that includes: [0014] (a) a first part including a
(meth)acrylate component, an organic peroxide and an
acetal-containing free radically curable component; and [0015] (b)
a second part including a (meth)acrylate component, and
benzoylthiourea derivatives or benzoylthiourethane derivatives.
[0016] In another aspect of the invention there is provided a
method of preparing a two-part adhesive composition which includes:
[0017] (a) forming a first part (A) including a (meth)acrylate
component, an organic peroxide and an acetal-containing free
radically curable component; and [0018] (b) forming a second part
(B) including a (meth)acrylate component, and benzoylthiourea
derivatives or benzoylthiourethane derivatives.
[0019] In yet another aspect, there is provided a method of bonding
a first surface to a second surface, which includes the step
of:
[0020] providing a two part composition which includes: [0021] (a)
a first part (A) including a (meth)acrylate component, an organic
peroxide and an acetal-containing free radically curable component;
and [0022] (b) a second part (B) including a (meth)acrylate
component, and benzoylthiourea derivatives or benzoylthiourethane
derivatives; where when the first and second parts are mixed and
applied to at least one substrate, the composition will have up to
about 5 minutes of open time and when the substrates are mated they
will have a cure time of about 20 minutes or less at 80.degree. C.
and a fixture time of less than 5 minutes.
[0023] In another aspect, the present invention there is provided
an adhesive composition which includes: [0024] (a) a (meth)acrylate
component; [0025] (b) a curative package comprising an organic
peroxide, and benzoylthiourea derivatives or benzoylthiourethane
derivatives; and [0026] (c) an acetal-containing free radically
curable component.
DETAILED DESCRIPTION
[0027] The adhesive compositions of this invention provide enhanced
adhesion to substrate surfaces constructed from a variety of
materials, many of which are metallic.
[0028] The present invention therefore provides adhesive
compositions, sometimes in a two part configuration which include a
first part containing a (meth)acrylate component, an organic
peroxide and an acetal-containing free radically curable component
and a second part containing a (meth)acrylate component, and
benzoylthiourea derivatives or benzoylthiourethane derivatives.
[0029] Among the substrates where enhanced adhesive and bonding
strength is achieved are metal substrates, such as mild steel,
stainless steel and aluminum, glass substrates (such as ink-coated
glass substrates), and various plastic substrates (such as
acrylics, polycarbonate, polycarbonate-ABS and nylon).
[0030] The combination of the Part (A) composition and the Part (B)
composition results in a curable composition suitable for use in
mating adhesively one substrate surface to another substrate
surface. One or more of the substrates may be constructed to form
an adhesive joint or a laminate. After curing, the reaction product
of the composition is an adhesive bond between the two substrate
surfaces.
[0031] While the two part compositions may be used in a variety of
commercial applications,'they are particularly useful in the
assembly of electronic display devices, such as hand-held phone and
computer devices.
Part (A)
(Meth)acrylate Component
[0032] Any suitable material which contains at least one group
having the following formula:
##STR00003##
where R is selected from H, halogen, or C.sub.1 to C.sub.10
hydrocarbyl, may be used.
[0033] Advantageously, the group is a (meth)acryloxy group. The
term "(meth)acryloxy" is intended to refer to both acrylate and
methacrylate, in which R is H or methyl, respectively. The useful
amount of the (meth)acrylate component typically ranges from about
20 percent by weight to about 80 percent by weight of the total
composition. Desirably, the inventive compositions contain from
about 50 percent by weight to about 70 percent by weight of
(meth)acrylate component.
[0034] The (meth)acrylate component may be present in the form of a
polymer, a monomer, or a combination thereof. When present in the
form of a polymer, the (meth)acrylate component may be a polymer
chain to which is attached at least one of the above-indicated
groups. The groups may be located at a pendant or a terminal
position of the backbone, or a combination thereof. Advantageously,
at least two such groups may be present, and may be located at
terminal positions. The (meth)acrylate component may have a polymer
chain, constructed from polyvinyl, polyether, polyester,
polyurethane, polyamide, epoxy, vinyl ester, phenolic, amino resin,
oil based, and the like, as is well known to those skilled in the
art, or random or block combinations thereof.
[0035] The polymer chain may be formed by polymerization of vinyl
monomers. Illustrative examples of such vinyl monomers are methyl
(meth)acrylate, (meth)acrylic acid, ethyl (meth)acrylate, n-propyl
(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,
isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl
(meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate,
n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl
(meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl
(meth)acrylate, phenyl (meth)acrylate, tolyl (meth)acrylate, benzyl
(meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl
(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl
(meth)acrylate, stearyl (meth)acrylate, glycidyl (meth)acrylate,
2-aminoethyl (meth)acrylate,
y-(meth)acryloyloxypropyltrimethoxysilane, (meth)acrylic
acid-ethylene oxide adduct, trifluoromethylmethyl (meth)acrylate,
2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl
(meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl
(meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl
(meth)acrylate, diperfluoromethylmethyl (meth)acrylate,
2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate,
2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl
(meth)acrylate, 2-perfluorohexadecylethyl (meth)acrylate,
ethoxylated trimethylolpropane triacrylate, trimethylol propane
trimethacrylate, dipentaerythritol monohydroxypentaacrylate,
pentaerythritol triacrylate, ethoxylated trimethylolpropane
triacrylate, 1,6-hexanedioldiacrylate, neopentyl glycoldiacrylate,
pentaerythritol tetraacrylate, 1,2-butylene glycoldiacrylate,
trimethylopropane ethoxylate tri(meth)acrylate, glyceryl
propoxylate tri(meth)acrylate, trimethylolpropane
tri(meth)acrylate, dipentaerythritol monohydroxy
penta(meth)acrylate, tri(propylene glycol) di(meth)acrylate,
neopentylglycol propoxylate di(meth)acrylate, 1,4-butanediol
di(meth)acrylate, polyethyleneglycol di(meth)acrylate,
triethyleneglycol di(meth)acrylate, butylene glycol
di(meth)acrylate and ethoxylated bisphenol A di(meth)acrylate.
These monomers may be used each alone or a plurality of them may be
copolymerized. Particularly desirable (meth)acrylate ester monomers
include those where the alcohol portion of the ester group contains
1-8 carbon atoms. For instance, 2-ethylhexyl methacrylate,
hydroxyethyl methacrylate, cyclohexyl methacrylate, ethyl
methacrylate, 1,3-butanedioldimethacrylate (BDMA), butyl
methacrylate and methyl methacrylate (MMA), are examples.
[0036] Particularly desirable however is tetrahydrofurfuryl
(meth)acrylate as at least a portion of the (meth)acrylate
component.
[0037] The amount of the (meth)acrylate component used in the Part
(A) composition may be from about 20 to about 95 percent by weight,
such as about 40 to about 75 percent by weight.
Acetal-Containing Free Radically Curable Component
[0038] As the acetal-containing free radically curable component,
compounds within the general structure below may be used:
##STR00004##
where R.sup.1 is H, CH.sub.3 or CN;
[0039] R.sup.2 is a multivalent C.sub.1 to C.sub.8 alkyl chain,
C.sub.6 to C.sub.12 aryl group or C.sub.3 to C.sub.8 cycloalkyl
group; and
[0040] n is 1-4.
##STR00005##
[0041] R.sup.2 is a divalent unsaturated C.sub.2-C.sub.40 linkage
(such as may be derived from a dicarboxylic acid selected from
maleic acid, fumaric acid, itaconic acid, glutaconic acid,
traumatic acid, glutinic acid and mesaconic acid.
##STR00006##
where R.sup.1 is C.sub.1 to C.sub.8 alkyl, C.sub.6 to C.sub.12 aryl
or C.sub.3 to C.sub.8 cycloalkyl; and
[0042] R.sup.2 is a divalent unsaturated C.sub.2-C.sub.60 linkage
(such as may be derived from a tricarboxylic acid selected from
citric acid, isocitric acid, aconitic acid and trimesic acid).
[0043] Specific examples of the acetal-containing (meth)acrylate
compound include those listed below:
##STR00007##
[0044] The amount of the acetal-containing (meth)acrylate compound
used in the Part (A) composition may be from about 1 to about 20
percent by weight, such as about 2.5 to about 10 percent by
weight.
Peroxy Initiators
[0045] A class of peroxy initiators particularly suitable to the
present invention is the hydroperoxy initiators. Of these, organic
hydroperoxides are particularly. Particularly preferred organic
hydroperoxides include, p-methane hydroperoxide, diisopropyl
benzene hydroperoxide, pinene hydroperoxide, methyl ethyl ketone
hydroperoxide, t-butyl-2-hydroxyethyl peroxide, t-butyl
peroxymaleic acid, cumene hydroperoxide (CHP), tertiary-butyl
hydroperoxide (TBH), and benzoyl peroxide (BP). Additionally,
inorganic peroxides and compositions such as peroxy esters as for
example t-butyl perbenzoate, benzophone peroxyesters and fluorenone
peroxyesters, peroxy carbonates and halogen containing compounds
having electronic structures which facilitate free radical
formation, esters which decompose to form free radicals are also
useful. The term "peroxy" is intended to mean peroxides,
hydroperoxides and peresters which are suitable for preparing
anaerobically curing system.
[0046] The peroxy polymerization initiators may be used in the Part
(A) compositions in amounts sufficient to perform their initiation
function. Useful, non-limiting amounts include about 0.25 percent
by weight to about 10 percent by weight based on the total
composition, and desirably about 1 percent by weight to about 3
percent by weight based on the total composition.
Free Radical Inhibitors
[0047] Free radical polymerization inhibitors may be used in the
present invention to prevent premature reaction prior to
mixing.
[0048] Numerous suitable free-radical polymerization inhibitors are
known in the art, and include quinones, hydroquinones,
hydroxylamines, nitroxyl compounds, phenols, amines, arylamines,
quinolines, phenothiazines, and the like. Particularly useful free
radical inhibitors include hydroquinone, tertiary butylhydroquinone
("TBHQ"), methyl hydroquinone, hydroxyethylhydroquinone,
phenothiazine, and NAUGARD-R (blend of N-alkyl substituted
p-phenylenediamines, from Crompton Corp.). One or more individual
free radical inhibitor components may also be combined.
[0049] The amount of the free radical inhibitor component used in
the Part (A) composition may be from 0 to about 1 percent by
weight, such as about 0.05 to 0.2 percent by weight.
Part (B)
(Meth)acrylate Component
[0050] The (meth)acrylate component used in part (B) may be any one
or more of the (meth)acrylates used in part (A).
[0051] The amount of the (meth)acrylate component used in the Part
(B) composition may be from about 20 to about 95 percent by weight,
such as about 40 to about 75 percent by weight.
Reactive Acid Component
[0052] The inventive compositions include an acid or acid ester.
Desirably, this component is only in the Part (B) composition.
Suitable acids or acid esters include phosphoric acid or
derivatives, phosphate acid esters, and sulfonic acids or
derivatives. A preferred reactive acid component is a phosphate
acid ester.
[0053] The acid monomer is a free-radical polymerizable acid
monomers, such as ethylenically unsaturated mono or polycarboxylic
acids, maleic acid and crotonic acid. Desirable ones include
methacrylic acid ("MAA") and acrylic acid. The reactive acid
component also modulates and decelerates the curing time of the
thermoset composition.
[0054] Suitable phosphate esters include those represented by the
formula:
##STR00008##
where here R.sup.1 is H or CH.sub.3, and R.sup.2 is H, or a radical
represented by the structure:
##STR00009##
where R.sup.1 is H or CH.sub.3. A particularly useful phosphate
ester is hydroxyl ethyl methacrylate ("HEMA") phosphate ester,
which is sold under the tradenames T-MULZ 1228 or HARCRYL 1228 or
1228M, each available from Harcross Chemicals, Kansas City, Kans.
Also included are structures with at least one strong acid "active
hydrogen" group, or with at least one phosphonic acid active
hydrogen group (R.sub.1R.sub.2POOH), such as hydroxyl ethyl
diphosphonic acid, phosphonic acid, and derivatives, or oligomeric
or polymeric structures with phosphonic acid functionality or
similar acid strength functionality.
[0055] The reactive acid component may be present from about 0.25
percent by weight to about 15 percent by weight of the total
composition.
Benzoylthiourea Derivatives or Benzoylthiourethane Derivatives
[0056] The benzoylthiourea derivatives or benzoylthiourethane
derivatives may be within general structure I
##STR00010##
where Z is O or N--R, where R is selected from hydrogen, alkyl,
alkenyl, hydroxyalkyl, hydroxyalkenyl, carbonyl, alkylene
(meth)acrylate, carboxyl, or sulfonato, or R' is a direct bond
attaching to the phenyl ring; R' is selected from hydrogen, alkyl,
alkenyl, cycloalkyl, aryl, hydroxyalkyl, hydroxyalkenyl, alkylene-
or alkenylene-ether, carbonyl, alkylene (meth)acrylate, carboxyl,
nitroso or sulfonato; X is halogen, alkyl, alkenyl, hydroxyalkyl,
hydroxyalkenyl, alkoxy, amino, carboxyl, nitroso, sulfonate,
hydroxyl or haloalkyl; and Y is --SO.sub.2NH--, --CONH--, --NH--,
and --PO(NHCONHCSNH.sub.2)NH--; and n is 0 or 1 and m is 1 or
2.
[0057] A more specific general structure is shown below:
##STR00011##
[0058] where R and R' are independently selected from hydrogen,
alkyl, alkenyl, aryl, hydroxyalkyl, hydroxyalkenyl, alkylene
(meth)acrylate, carbonyl, carboxyl, or sulfonato, or R and R' taken
together form a carbocyclic or hetero atom-containing ring, or R'
is a direct bond attaching to the phenyl ring; X is halogen, alkyl,
alkenyl, cycloalkyl, hydroxyalkyl, hydroxyalkenyl, alkoxy, amino,
alkylene- or alkenylene-ether, alkylene (meth)acrylate, carbonyl,
carboxyl, nitroso, sulfonate, hydroxyl or haloalkyl; and Y is
--SO.sub.2NH--, --CONH--, --NH--, and --PO(NHCONHCSNH.sub.2)NH--;
and n is 0 or 1 and m is 1 or 2.
[0059] More specifically, the benzoylthiourea or
benzoylthiourethane derivatives may be within structures II or IIA,
respectively
##STR00012##
where R, R', Z, X, Y, and n are as defined above.
[0060] More specific examples of the benzoylthiourea or
benzoylthiourethane derivatives within structures II and IIA,
respectively, are set forth below
##STR00013##
where R, X, Y, and n are as defined above, and X' is defined as
X.
[0061] Alternatively, the benzoylthiourea or benzoylthiourethane
derivatives within structure I may be a bis version, where R' is a
linker. That is,
##STR00014##
where R, R', X, Y, and n are as defined above, and m is 2.
[0062] And even more specifically, the benzoylthiourea or
benzoylthiourethane derivatives may be
##STR00015## ##STR00016## ##STR00017## ##STR00018##
[0063] The benzoylthiourea or benzoylthiourethane derivatives may
be employed in the adhesive compositions in amounts useful to
enhance the adhesive properties of the compositions. For example,
they may be present in amounts of about 0.25 percent by weight to
about 10 percent by weight, such as about 1 percent by weight to
about 5 percent by weight of the total composition.
Constituents Used in Either or Both of Part (A) or Part (B)
Plasticizers
[0064] Plasticizers may be used in either part or in both parts of
the two part composition. Plasticizers may be any liquid or soluble
compound that assists with the flexibility of the reactive portion
of the composition and/or may act as a carrier vehicle for other
components of the composition. Examples include aromatic
sulfonamides, aromatic phosphate esters, alkyl phosphate esters,
dialkylether aromatic esters, polymeric plasticizers, dialkylether
diesters, polyglycol diesters, tricarboxylic esters, polyester
resins, aromatic diesters, aromatic triesters (trimellitates),
aliphatic diesters, epoxidized esters, chlorinated hydrocarbons,
aromatic oils, alkylether monoesters, naphthenic oils, alkyl
monoesters, paraffinic oils, silicone oils, di-n-butyl phthalate,
diisobutyl phthalate, di-n-hexyl phthalate, di-n-hepytl phthalate,
di-2-ethylhexyl phthalate, 7c,9c-phthalate (linear and branched),
diisoctyl phthalate, linear 6c,8c,10c phthalate, diisononyl
phthalate, linear 8c-10c phthalate, linear 7c-11c phthalate,
diisodecyl phthalate, linear 9c-11c phthalate, diundecyl phthalate,
diisodecyl glutarate, di-2-ethylhexyl adipate, di-2-ethylhexyl
azelate, di-2-ethylhexyl sebacate, di-n-butyl sebacate, diisodecyl
adipate, triethylene glycol caprate-caprylate, triethylene glycol
2-ethylhexanote, dibutoxyethyl adipate, dibutoxyethoxyethyl
adipate, dibutoxyethoxyethyl formal, dibutoxyethoxyethyl sebacate,
tri-2-ethylhexyl trimellitate, tri-(7c-9c(linear)) trimellitate,
tri-(8c-10c(linear)) trimellitate, triethyl phosphate, triisopropyl
phenyl phosphate, tributyl phosphate, 2-ethylhexyl diphenyl
phosphate, trioctyl phosphate, isodecyl diphenyl phosphate
triphenyl phosphate, triaryl phosphate synthetic, tributoxyethyl
phosphate, tris(-chloroethyl) phosphate, butylphenyl diphenyl
phosphate, chlorinated organic phosphate, cresyl diphenyl
phosphate, tris(dichloropropyl) phosphate, isopropylphenyl diphenyl
phosphate, trixylenyl phosphate, tricresyl phosphate, diphenyl
octyl phosphate. Combinations of plasticizers are useful.
[0065] The amount of the plasticizer used in the composition as a
whole may be from 0 to about 5 percent by weight, such as about 0.1
to about 1 percent by weight of the total composition.
Block Copolymers
[0066] When used, the block copolymer may be any block copolymer
capable of contributing to the physical properties desired for the
disclosed composition. The block copolymers may be present in
either or both parts of the two part composition.
[0067] The block copolymer rubber may be constructed using blocks
of either butadiene or isoprene with styrene (for example, SBS,
SIS, SEGS and SB), commercial examples of which are available from
Shell Chemical Co. as KRATON D-1116 and other KRATON D-grade
elastomers from Dexco as VECTOR 2411IP.
[0068] Other elastomers with Tg below about 25.degree. C., which
are soluble in methacrylate/acrylate monomers, can be used in place
of the block copolymer rubbers. Examples of such are the
homopolymer of epichlorohydrin and its copolymers with ethylene
oxide, available from Zeon Chemicals as HYDRIN, acrylate rubber
pellets, available from Zeon as HYTEMP, polyisoprene rubber,
polybutadiene rubber, nitrile rubber, and SBR rubber (random
copolymer of butadiene and styrene).
[0069] Still other block copolymers may be a styrene maleic
anhydride copolymer, represented by the formula:
##STR00019##
where v is from 1 to 12; w is from 1 to 6; and n is from 1 to
50.
[0070] Styrene maleic anhydride copolymers are well known and some
of which are available commercially from Sartomer Company, Inc.,
Exton, PA under the trade name SMA EF80, for example. Styrene
maleic anhydride copolymers represent the copolymerization product
of styrene and maleib anhydride and are characterized by
alternating blocks of styrene and maleic anhydride moieties.
[0071] Amphiphilic block copolymers may be particularly desirable.
Arkema offers for sale commercially an amphiphilic block copolymer
under the trademark NANOSTRENGTH. Such block copolymers are
currently available in two versions: SBM and MAM. The SBM copolymer
is reportedly made of polystyrene, 1,4-polybutadiene and
syndiotactic poly(methyl methacrylate).
[0072] In addition, a polymer material constructed from polymethyl
methacrylate ("PMMA") and polybutyl acrylate ("PB") may be used
too. Polymer materials within this class are referred to as
polymethylmethacrylate-block-polybutylacrylate-block
polymethylmethacrylate copolymers ("MAM").
[0073] As reported by Arkema, MAM is a triblock copolymer,
consisting of about 70% PMMA and 30% PB. MAM is constructed from
distinct segments, which provides for the ability to self-assemble
at the molecular scale. That is, M confers hardness to the polymer
and A confers elastomeric properties to the polymer.
[0074] A hard polymer segment tends to be soluble in
(meth)acrylates, whereas the elastomeric segments provide toughness
to the polymeric (meth)acrylate, which forms upon cure. MAM also
reinforces mechanical properties, without compromising inherent
physical properties. MAM is commercially available under the
tradename NANOSTRENGTH, at present under several different grades
i.e., E-21 and M-52N.
[0075] Arkema promotes the NANOSTRENGTH product line as an acrylic
block copolymer that is miscible with many polymers, most of which
according to the manufacturer are major industrial epoxy resins.
See also U.S. Pat. No. 6,894,113 (Court), where in its abstract the
'113 patent speaks to a thermoset material with improved impact
resistance. The impact resistance is derived from 1 to 80% of an
impact modifier comprising at least one copolymer comprising S-B-M,
B-M and M-B-M blocks, where each block is connected to the other by
a covalent bond or of an intermediary connected to one of the
blocks by a covalent bond and to the other block by another
covalent bond, M is a PMMA homopolymer or a copolymer comprising at
least 50% by weight of methyl methacrylate, B is incompatible with
the thermoset resin and with the M block and its glass transition
temperature Tg is less than the operating temperature of the
thermoset material, and S is incompatible with the thermoset resin,
the B block and the M block and its Tg or its melting temperature
is greater than the Tg of B.
[0076] Another commercially available example of an amphiphilic
block copolymer is a polyether block copolymer known to the trade
as FORTEGRA 100, from Dow Chemical Co. Dow describes FORTEGRA 100
as a low viscosity toughening agent designed for use as a high
efficiency second phase, in amine cured epoxy systems. FORTEGRA 100
is reported to provide improved toughness without significantly
affecting the viscosity, glass transition temperature, corrosion
resistance, cure rate or chemical resistance of the final coating
or composition. FORTEGRA 100 is also reported to be useful for
formulation into standard bisphenol A and bisphenol F epoxy systems
as it does not participate in the epoxy cure reaction. As a second
phase toughening agent, FORTEGRA 100 is promoted as being effective
when formulated at a specific volume fraction of the finish film or
part, typically 3% to 8% by dry volume is said to achieve the
toughening effect.
[0077] Additional block copolymers include those which comprise
both hydrophobic and hydrophilic segments or portions, of the
general formula:
--[(R.sup.1).sub.v--(R.sup.2).sub.w].sub.n--
where here R.sup.1 is independently a hydrophobic olefin, such as
ethylene, propylene, 1-butene, 1-hexene, 3-methyl-1-pentene, or
4-methyl-1-pentene or a polymerizable hydrophobic aromatic
hydrocarbon such as styrene; each R.sup.2 is a hydrophilic acid
anhydride, such as maleic anhydride; v is from 1 to 12; w is from 1
to 6; and n is from 1 to 50.
[0078] The ratio of the hydrophobic segments to the hydrophilic
segments in the styrene maleic anhydride block copolymer may be at
least 2:1, such as between 3:1 and 12:1. The hydrophilic segments
in the block copolymer should comprise an anhydride, such as maleic
anhydride. The hydrophobic segments in the block copolymer should
comprise at least one of ethylene, propylene, 1-butene, 1-hexene,
3-methyl-1-pentene, 4-methyl-1-pentene, or styrene. Desirably, the
block copolymer should be prepared with the hydrophilic segments
comprising maleic anhydride and the hydrophobic segments comprising
styrene.
[0079] Reference to the following U.S. patent documents shows
amphiphilic block copolymers suitable for use herein, and as such
are incorporated herein by reference. U.S. Pat. No. 7,745,535
(Schmidt) is directed to and claims an amphiphilic multiblock
copolymer where at least one block is a profiled block consisting
of a) a hydrophilic middle block made from one or more monomeric
units selected from acrylic acid, methacrylic acid, and the salts,
esters, anhydrides and amides of acrylic acid and methacrylic acid;
dicarboxylic acid anhydrides; carboxyethyl acrylate; and
acrylamides; and b) hydrophobic end blocks where the multiblock
copolymer is water insoluble, water indispersible, and not soluble
or dispersible in C.sub.1-3 alcohols.
[0080] U.S. Pat. No. 7,820,760 (Pham) is directed to and claims a
curable adhesive epoxy resin composition including (a) an epoxy
resin; (b) an amphiphilic block copolymer containing at least one
epoxy resin miscible block segments and at least one epoxy resin
immiscible block segments (where the immiscible block segment
comprises at least one polyether structure provided that the
polyether structure of the immiscible block segment contains at
least one or more alkylene oxide monomer units having at least four
carbon atoms); and (c) at least one curing agent. The amphiphilic
block copolymer in the '760 patent is an all polyether block
copolymer such as a PEO-PBO diblock copolymer or a PEO-PBO-PEO
triblock copolymer. The amphiphilic block copolymer is present in
an amount such that when in the '760 patent the epoxy resin
composition is cured, the bond strength of the resulting cured
epoxy adhesive resin composition increases compared to an epoxy
resin composition without the amphiphilic polyether block
copolymer.
[0081] U.S. Pat. No. 7,670,649 (Hoyles) is directed to and claims a
curable ambient cure high-solids coating composition including (a)
an epoxy resin; (b) an amphiphilic block copolymer containing at
least one epoxy resin miscible block segment (where the immiscible
block segment comprises at least one polyether structure provided
that the polyether structure of the immiscible block segment
contains at least one or more alkylene oxide monomer units) and at
least one epoxy resin immiscible block segment; and (c) a
sufficient amount of a nitrogen-containing curing agent to cure the
coating composition at ambient temperature of less than about
60.degree. C. When the epoxy resin composition is cured, the
toughness of the resulting cured epoxy resin composition is
increased.
[0082] U.S. Pat. No. 6,887,574 (Dean) is directed to and claims a
curable flame retardant epoxy resin composition including (a) at
least one flame retardant epoxy resin; (b) at least one amphiphilic
block copolymer; and (c) a curing agent. Such components are
present in the curable composition in the appropriate amounts and
ratios such that, upon curing, the block copolymer self-assembles
into a nano structure morphology, such as a worm-like micelle
morphology. The resulting cured product is reported to have a
remarkably increased high fracture resistance; and allows the use
of flame retardant epoxies in applications where fracture
resistance is an issue.
[0083] U.S. Patent Application Publication No. 2008/0287595
(Verghese) is directed to a composition comprising (1) a
thermosettable resin selected from an epoxy resin, an epoxy vinyl
ester resin, an unsaturated polyester resin or a mixture thereof,
and (2) an amphiphilic mock copolymer dispersed in the
thermosettable resin. In addition, fiber-reinforced plastics (FRP),
coatings and composites prepared from the composition are provided
as well.
[0084] International Patent Publication No. WO 2010/008931
(Turakhia) is directed to a structural composite that uses a block
copolymer toughening agent to increase the fracture resistance
(toughness) of the structural composite. The structural composite
comprises (i) a carbon fiber reinforcing material and (ii) a
thermosettable resin composition; wherein the thermosettable resin
composition comprises (a) a thermosettable resin and (b) at least
one block copolymer toughening agent.
[0085] International Patent Publication No. WO 2009/018193
(Verghese) is directed to curable compositions, cured compositions,
and methods of forming the same, including an epoxy resin, a curing
agent, an amphiphilic toughening agent, and an inorganic
nanofiller, where the toughening agent forms a second phase having
at least one dimension being on the nanometer scale.
[0086] The block copolymer may be used herein in an amount up to
about 50 weight percent, desirably from 5 to 40 weight percent
based on the total weight of the adhesive composition.
[0087] The glass transition temperature ("Tg") of the block
copolymer should be above about 40.degree. C. In one embodiment,
the Tg of the block copolymer is between about 40.degree. C. and
about 155.degree. C.
[0088] The Tg of a polymer is the temperature at which the polymer
becomes brittle on cooling or soft on heating. More specifically,
Tg defines a pseudo second order phase transition in which a
polymer yields, on cooling, a glassy structure with properties
similar to those of a crystalline material. Above Tg, the polymer
becomes soft and capable of plastic deformation without fracture.
While the Tg is occasionally described as the "softening
temperature" of a polymer, it is not uncommon for the polymer to
begin softening at a temperature below the Tg. This is because, due
to the nature of many non-crystalline polymers, the softening of
the polymer may occur over a temperature range rather than abruptly
at a single temperature value. Tg generally refers to the middle
point of this range even though the polymer may begin to soften at
a different temperature. For purposes of this application, the Tg
of a polymer refers to the value as determined by ASTM E-1356.
[0089] The amount of the block copolymer used in the composition as
a whole may be from about 5 percent by weight to about 75 percent
by weight, such as about 10 percent by weight to about 50 percent
by weight of the total composition.
Other Additives
[0090] Either or both parts may contain additional additives, such
as fillers, lubricants, thickeners, and coloring agents. The
fillers provide bulk without sacrificing strength of the adhesive
and can be selected from high or low density fillers. Also, certain
fillers, such as silica, can confer rheological modification or
small particle reinforcements. Commercially available examples
include Cab-O-Sil 610 and AEROSIL R8200.
[0091] Of particular interest are low density fillers, because the
resulting final product has an otherwise lower density than a
product without the filler, yet has essentially the same strength
characteristics as if the filler was not present.
[0092] Also, core shell polymers may be desirable. The core shell
polymer is desirably a graft copolymer of the "core shell" type, or
may also be a "shell-less" cross-linked rubbery particulate, such
as acrylonitrile-butadiene-styrene ("ABS"),
methacrylate-butadiene-styrene ("MBS"), and
methacrylate-acrylonitrile-butadiene-styrene ("MABS"). BLENDEX 338
is an ABS powder from GE Plastics.
Packaging and Mixing
[0093] When prepared in a two part format, each of Part (A) and
Part (B) are packaged in separate containers, such as bottles,
cans, tubes, or drums.
[0094] Part (A) and Part (B) are mixed in a ratio of about 1 to
about 10 Part (a) to about 10 to about 1 Part (b). Desirably, the
ratio of Part (A) to Part (B) is about 1 Part (A) to about 1 Part
(B).
[0095] The mixing of the two parts can employ a mixing nozzle,
which has fluid inputs for the two components, performs a suitable
mixing operation, and dispenses the adhesive mixture directly onto
the surface to be bonded. An example of a commercially available
mixing and dispensing device is MIXPAC.RTM., available from
ConProTec, Salem, N.H. The two parts can also be mixed manually in
a bowl, bucket, or the like, but the operator needs to ensure that
the mixing is thorough. As an aid to ensuring that mixing is
complete, each part can be formulated with a dye or pigment, so
that after mixing, a third color is formed. For example, one part
may have a yellow dye, the other part may have a blue dye, so that
after mixing, the complete adhesive composition will be green.
[0096] The inventive compositions are excellent adhesives and
sealants. On application to a first surface, such as a sheet of
metal, fabric or plastic that can be incorporated into a laminated
material, a second surface will be mated with the first surface and
the two surfaces will be bonded together as the adhesive cures. A
further advantage is that no surface preparation is required to
bond clean substrates.
[0097] By the term "curing" is meant that the chemical reaction
converting the fluid mix to the solid bond of this invention. The
curing process of this composition is exothermic, and may reach a
temperature of about 120.degree. C. or so, when a large bead of
adhesive is used.
[0098] After mixing, the adhesive compositions fully cure in about
20 minutes at about 80.degree. C. and within about 24 hours at room
temperature. Fixture times range from about 7 to about 10 minutes,
at which time the bond will support a 3 Kg load.
EXAMPLES
[0099] Initially, certain acetal-containing (meth)acrylates were
synthesized as follows:
Example A
Preparation of 1-(4-[1-(prop-2-enoyloxy)ethoxy]butoxy)ethyl
prop-2-enoate [butanediol diacetal diacrylate ("BDDA")]
[0100] A 250 ml 3 neck round bottom flask was charged with 1,4
butanediol divinyl ether (50 ml, 0.32 mol) and methyl ether
hydroquinone (0.302 g, 0.0024 mol), a stirrer bar and fitted with a
reflux condenser, contact thermometer and dropping funnel. The
reaction vessel was heated to a temperature of 80.degree. C. and
acrylic acid (46.1 g, 0.64 mol) was added dropwise with stirring as
the reaction temperature was maintained at 80.degree. C. for 5
hours. The solution was allowed to cool and was then washed with a
saturated aqueous solution of sodium bicarbonate, followed by a
washing with a brine solution. The remaining organic layer was
dried over magnesium sulfate and dried under vacuum to leave a
colourless oil. Yield: 63.47 g. IR analysis showed the --OH peak of
the acrylic acid was no longer present.
Example B
Preparation of 1-[4-[1-(methylprop-2-enoyloxy)ethoxy]butoxy]ethyl
methylprop-2-enoate [butanediol diacetal dimethacrylate
("BDDMA")]
[0101] A 250 ml 3 neck round bottom flask was charged with 1,4
butanediol divinyl ether (50 ml, 0.32 mol) and methyl ether
hydroquinone (0.302 g, 0.0024 mol), a stirring bar and fitted with
a reflux condenser, contact thermometer and dropping funnel. The
reaction vessel was heated to 80.degree. C. and methacrylic acid
(55.1 g, 0.64 mol) was added dropwise while the solution was
stirred. The reaction vessel was maintained at a temperature of
80.degree. C. for 5 hours, after which time the reaction mixture
was allowed to cool to room temperature. The reaction mixture was
thereafter washed with a saturated aqueous solution of sodium
bicarbonate, followed by a washing with a brine solution. The
remaining organic layer was dried over magnesium sulfate and dried
under vacuum to leave a colourless oil. Yield: 67.23 g. IR analysis
showed the --OH peak of the acrylic acid was no longer present.
Example C
Preparation of 1,4-bis(1-propoxyethyl) (2Z)-but-2-enediote [maleic
acid dibutyl acetal ("MADBA")]
[0102] A 250 ml 3 neck round bottom flask was charged with
butanevinyl ether (50 ml, 0.39 mol) and methyl ether hydroquinone
(0.302 g, 0.0024 mol), a stirrer bar and fitted with a reflux
condenser, contact thermometer and dropping funnel. The reaction
mixture was heated to 40.degree. C. and maleic acid (68.44 g, 0.64
mol) dissolved in methanol (200 ml) was added dropwise while the
solution was stirred. The temperature of the reaction vessel was
maintained at 80.degree. C. for 5 hours. The solution was allowed
to cool and was then washed with a saturated aqueous solution of
sodium bicarbonate, followed by a washing with a brine solution.
The remaining organic layer was dried over magnesium sulfate and
dried under vacuum to leave a colourless oil. Yield was 99.66g of
product. IR analysis showed the --OH peak of the acrylic acid was
no longer present.
Example D
Preparation of 1-propoxyethyl prop-2-enoate [butylacetal acrylate
("BAA")]
[0103] A 250 ml 3 neck round bottom flask was charged with
butanevinyl ether (50 ml, 0.39 mol) and methyl ether hydroquinone
(0.302 g, 0.0024 mol), a stirrer bar and fitted with a reflux
condenser, contact thermometer and dropping funnel. The flask
contents was heated to 40.degree. C. and acrylic acid (28.1 g, 0.39
mol) was added dropwise while the solution was stirred. The
temperature of the contents of the vessel was maintained at
40.degree. C. for 5 hours. The solution was allowed to cool and was
then washed with a saturated aqueous solution of sodium
bicarbonate, followed by a washing with a brine solution. The
remaining organic layer was dried over magnesium sulfate and dried
under vacuum to leave a colourless oil. Yield was 50.46 g of
product. IR analysis of the product showed that the --OH peak of
the acrylic acid was no longer present.
Two-Part (Meth)acrylate Compositions
[0104] The following two part adhesive compositions were prepared
as set forth in Table I below. The Part (A) composition was
prepared by mixing together the components in the amounts (phr) as
listed to form a homogeneous blend, using mixing speeds of about
2500 RPMs for about 2-3 minutes. The
[0105] Part (B) composition was similarly separately formed. The
Part (A) composition was used without change throughout the
examples.
TABLE-US-00001 TABLE 1 Part A Constituents Wt. % 30 wt. % Magnum
3904 82.5 ABS Rubber in THFMA Methacrylic Acid 10 Cyclohexyl BTU 5
Hydrophobic Silica 2.5
[0106] Table 2 below shows a list of the Part B compositions, which
are otherwise the same save for the acetal-containing
(meth)acrylate compound chosen and a control formulation (Part
(B1)) without such a compound.
TABLE-US-00002 TABLE 2 Part B B1 B2 B3 B4 B5 Constituents Wt. % Wt.
% Wt. % Wt. % Wt. % 30 wt % Magnum 3904 92.5 87.5 87.5 87.5 87.5
ABS Rubber in THFMA Hydrophobic Silica 2.5 2.5 2.5 2.5 2.5 Cumene
Hydroperoxide 5 5 5 5 5 BDDA -- 5 -- -- -- BDDMA -- -- 5 -- --
MADBA -- -- -- 5 -- BAA -- -- -- -- 5
Physical Properties/Performance
[0107] Table 3 below shows the results observed and recorded for
tensile shear values obtained according to ASTM D3163 when using an
adhesive formulation with a Part (B) Composition from Table 2
above. These Part (B) Compositions were mixed in equal parts by
weight with the Part (A) Composition from Table 1.
[0108] Inked glass substrates were bonded to PC-ABS substrates with
the Part (A)/Part (B) combinations mixed above.
[0109] To initiate debonding, the bonded lap shear substrates were
placed in an oven at a temperature of 80.degree. C. for 10 minutes
after room temperature curing for 24 hours. After removal from the
oven, the samples were allowed to cool under ambient conditions for
5 minutes before being evaluated for bond strength.
TABLE-US-00003 TABLE 3 Part B/Acetal Monomer B1 B2 B3 B4 B5
Physical Property None BDDA BDDMA MADBA BAA Tensile Shear, 24 hour
489 519 457 555 86 cure at room temp (Psi) Tensile shear, 24 hour
450 18 18 13 8 cure at room temp and oven heating for 10 min at
80.degree. C. (Psi) % reduction in bond 9.2 96.5 97.1 97.7 90.7
strengths post oven heating
[0110] The results shown in Table 3 demonstrate that inclusion of
an acetal-containing (meth)acylate enables debonding of these
bonded substrates after oven heating for 10 minutes at 80.degree.
C. compared to the control.
Environmental Resistance
[0111] Ink coated glass substrates were bonded to PC-ABS substrates
using these Part (A)/Part (B) combinations as above. After 24 hours
of curing at room temperature. The bonded lap shears were stored in
a humidity chamber for 10 days in an 85.degree. C./95% relative
humidity environment. The samples were evaluated after conditioning
for a period of 1 hour under ambient conditions. Table 4 below
shows the bond strengths after heat/humidity conditioning in
comparison to bond strengths after 24 hour room temperature
cure.
TABLE-US-00004 TABLE 4 Part B/Acetal Monomer B1 B2 B3 B4 B5
Physical Property None BDDA BDDMA MADBA BAA Tensile Shear, 24 hour
489 519 457 555 86 cure at room temp (Psi) Tensile shear post 10
590 665 475 100 76 days at 85.degree. C./95% relative humidity
[0112] The results observed and recorded in Table 4 show that for
the control (B1) and for the BDDA- and BDDMA-containing
compositions (B2 and B3, respectively) tensile shear strength
performance is comparable. However, the remaining compositions with
the other acetal-containing (meth)acrylates (B4 and B5) there is a
drop-off in tensile shear strength after the humid/heat ageing
test.
[0113] BDDA-containing compositions demonstrated good performance
under demanding environmental conditions. For instance, results of
thermal cycling on bonded inked glass to PC-ABS lap shears are
shown in Table 5.
[0114] Thermal cycle chamber parameters: 20 cycles of
25.degree./95% RH for 1.5 hours, ramped to 65.degree./95% RH for 4
hours, then ramped to 30.degree. C./95% RH for 1.5 hours and left
at 30.degree. C./95% RH for 1 hour. Lap shear specimens were then
removed and left at room temperature for 24 hours.
TABLE-US-00005 TABLE 5 Initial Post Thermal Cycling Part B (psi)
(psi) B1 (No acetal monomer) 489 488 B2 (5 wt. % BDDA) 519 457
[0115] The results indicate that the debondable formulation shows
good thermal cycling resistance.
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